freebsd-dev/sys/geom/geom_kern.c
Konstantin Belousov d5446cc8f4 Remove unneeded Giant locking around kthreads creation.
Sponsored by:	The FreeBSD Foundation
2016-05-20 08:28:11 +00:00

230 lines
6.6 KiB
C

/*-
* Copyright (c) 2002 Poul-Henning Kamp
* Copyright (c) 2002 Networks Associates Technology, Inc.
* All rights reserved.
*
* This software was developed for the FreeBSD Project by Poul-Henning Kamp
* and NAI Labs, the Security Research Division of Network Associates, Inc.
* under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
* DARPA CHATS research program.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The names of the authors may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/eventhandler.h>
#include <sys/malloc.h>
#include <sys/bio.h>
#include <sys/sysctl.h>
#include <sys/proc.h>
#include <sys/unistd.h>
#include <sys/kthread.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/sbuf.h>
#include <sys/sched.h>
#include <sys/sx.h>
#include <geom/geom.h>
#include <geom/geom_int.h>
MALLOC_DEFINE(M_GEOM, "GEOM", "Geom data structures");
struct sx topology_lock;
static struct proc *g_proc;
static struct thread *g_up_td;
static struct thread *g_down_td;
static struct thread *g_event_td;
int g_debugflags;
int g_collectstats = 1;
int g_shutdown;
int g_notaste;
/*
* G_UP and G_DOWN are the two threads which push I/O through the
* stack.
*
* Things are procesed in a FIFO order, but these threads could be
* part of I/O prioritization by deciding which bios/bioqs to service
* in what order.
*
* We have only one thread in each direction, it is believed that until
* a very non-trivial workload in the UP/DOWN path this will be enough,
* but more than one can actually be run without problems.
*
* Holding the "mymutex" is a debugging feature: It prevents people
* from sleeping in the UP/DOWN I/O path by mistake or design (doing
* so almost invariably result in deadlocks since it stalls all I/O
* processing in the given direction.
*/
static void
g_up_procbody(void *arg)
{
thread_lock(g_up_td);
sched_prio(g_up_td, PRIBIO);
thread_unlock(g_up_td);
for(;;) {
g_io_schedule_up(g_up_td);
}
}
static void
g_down_procbody(void *arg)
{
thread_lock(g_down_td);
sched_prio(g_down_td, PRIBIO);
thread_unlock(g_down_td);
for(;;) {
g_io_schedule_down(g_down_td);
}
}
static void
g_event_procbody(void *arg)
{
thread_lock(g_event_td);
sched_prio(g_event_td, PRIBIO);
thread_unlock(g_event_td);
g_run_events();
/* NOTREACHED */
}
int
g_is_geom_thread(struct thread *td)
{
return (td == g_up_td || td == g_down_td || td == g_event_td);
}
static void
geom_shutdown(void *foo __unused)
{
g_shutdown = 1;
}
void
g_init(void)
{
g_trace(G_T_TOPOLOGY, "g_ignition");
sx_init(&topology_lock, "GEOM topology");
g_io_init();
g_event_init();
g_ctl_init();
kproc_kthread_add(g_event_procbody, NULL, &g_proc, &g_event_td,
RFHIGHPID, 0, "geom", "g_event");
kproc_kthread_add(g_up_procbody, NULL, &g_proc, &g_up_td,
RFHIGHPID, 0, "geom", "g_up");
kproc_kthread_add(g_down_procbody, NULL, &g_proc, &g_down_td,
RFHIGHPID, 0, "geom", "g_down");
EVENTHANDLER_REGISTER(shutdown_pre_sync, geom_shutdown, NULL,
SHUTDOWN_PRI_FIRST);
}
static int
sysctl_kern_geom_conftxt(SYSCTL_HANDLER_ARGS)
{
int error;
struct sbuf *sb;
sb = sbuf_new_auto();
g_waitfor_event(g_conftxt, sb, M_WAITOK, NULL);
error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1);
sbuf_delete(sb);
return error;
}
static int
sysctl_kern_geom_confdot(SYSCTL_HANDLER_ARGS)
{
int error;
struct sbuf *sb;
sb = sbuf_new_auto();
g_waitfor_event(g_confdot, sb, M_WAITOK, NULL);
error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1);
sbuf_delete(sb);
return error;
}
static int
sysctl_kern_geom_confxml(SYSCTL_HANDLER_ARGS)
{
int error;
struct sbuf *sb;
sb = sbuf_new_auto();
g_waitfor_event(g_confxml, sb, M_WAITOK, NULL);
error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1);
sbuf_delete(sb);
return error;
}
SYSCTL_NODE(_kern, OID_AUTO, geom, CTLFLAG_RW, 0, "GEOMetry management");
SYSCTL_PROC(_kern_geom, OID_AUTO, confxml, CTLTYPE_STRING|CTLFLAG_RD,
0, 0, sysctl_kern_geom_confxml, "",
"Dump the GEOM config in XML");
SYSCTL_PROC(_kern_geom, OID_AUTO, confdot, CTLTYPE_STRING|CTLFLAG_RD,
0, 0, sysctl_kern_geom_confdot, "",
"Dump the GEOM config in dot");
SYSCTL_PROC(_kern_geom, OID_AUTO, conftxt, CTLTYPE_STRING|CTLFLAG_RD,
0, 0, sysctl_kern_geom_conftxt, "",
"Dump the GEOM config in txt");
SYSCTL_INT(_kern_geom, OID_AUTO, debugflags, CTLFLAG_RWTUN,
&g_debugflags, 0, "Set various trace levels for GEOM debugging");
SYSCTL_INT(_kern_geom, OID_AUTO, notaste, CTLFLAG_RW,
&g_notaste, 0, "Prevent GEOM tasting");
SYSCTL_INT(_kern_geom, OID_AUTO, collectstats, CTLFLAG_RW,
&g_collectstats, 0,
"Control statistics collection on GEOM providers and consumers");
SYSCTL_INT(_debug_sizeof, OID_AUTO, g_class, CTLFLAG_RD,
SYSCTL_NULL_INT_PTR, sizeof(struct g_class), "sizeof(struct g_class)");
SYSCTL_INT(_debug_sizeof, OID_AUTO, g_geom, CTLFLAG_RD,
SYSCTL_NULL_INT_PTR, sizeof(struct g_geom), "sizeof(struct g_geom)");
SYSCTL_INT(_debug_sizeof, OID_AUTO, g_provider, CTLFLAG_RD,
SYSCTL_NULL_INT_PTR, sizeof(struct g_provider), "sizeof(struct g_provider)");
SYSCTL_INT(_debug_sizeof, OID_AUTO, g_consumer, CTLFLAG_RD,
SYSCTL_NULL_INT_PTR, sizeof(struct g_consumer), "sizeof(struct g_consumer)");
SYSCTL_INT(_debug_sizeof, OID_AUTO, g_bioq, CTLFLAG_RD,
SYSCTL_NULL_INT_PTR, sizeof(struct g_bioq), "sizeof(struct g_bioq)");